Dutch researchers at the University of Groningen claim they can 3D print teeth made of anti-microbial plastic. This anti-microbacterial plastic can kill 99% of bacteria which cause tooth decay. Quaternary ammonium salts inside existing dental resin polymers can prevent tooth decay, so you never have to worry about losing teeth again.
Source: https://www.theguardian.com/technology/2015/oct/31/3d-printing-plastic-replacement-teeth